


when the room is too silent and your heart beats too loud

by cathrheas



Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Cowgirl Position, F/M, Heavy Angst, Jealousy, Porn with Feelings, Pseudo-Incest, References to Depression, Silver Snow spoilers, all-around spoilers tbh, maybe ooc idk
Language: English
Status: Completed
Published: 2019-09-02
Updated: 2019-09-02
Packaged: 2020-10-05 21:42:31
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,859
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20495789
Author URL: https://archiveofourown.org/users/cathrheas/pseuds/cathrheas
Summary: Rhea, despite her flaws, is still the only one that really understands, but for how long?





	when the room is too silent and your heart beats too loud

**Author's Note:**

> OK you know what. I'm gonna say it. Rhea did some bad things but she's lonely and she's baby. PERIODT >:(
> 
> also to explain the tag...both rhea and seteth ARE direct descendants of the goddess which goes a little farther than your average "we're all children under god!!11!" so i figured the tag would fit just for warning purposes. however their possible relationship as siblings wasn't in my mind while i was writing this if that makes sense
> 
> whatever. they fucking

Someone like Seteth should be able to sleep. He isn’t the perfect man, by any means, but the issue of not sleeping seemed so juvenile to him. Like a colicky baby that tossed and turned all night. He had been alive too long,  _ too _ long, to lay awake at night.

But then again, maybe being alive for that long was the problem.

Immortality was one thing in fiction, or in theory. You never had to worry about mistakes, about downfalls, because nothing was really permanent. But the loneliness was a fixture for him. It wasn’t a fantasy. It was real, and it came with real consequences. Even with Flayn, for so many years, there was nobody who understood him. They didn’t understand how it felt, to know that falling in love again would mean watching another loved one die. Nobody felt that same loneliness.

Except for Rhea.

One might argue that Rhea felt it more strongly than he did. At least he had Flayn. And, of course, he and Flayn loved Rhea with all of their heart, but there was nobody who felt as desperate and solitary as Rhea. She didn’t show it, Seteth knew, but her sanity was being chipped away at. He should have known how bad it had gotten when that professor took on the appearance of the Goddess. When he found out that it was Rhea’s doing.

As he rolled out of bed and made his way to her room, he told her it was for her sake. She was lonely, isolated. She needed someone. Byleth would never truly understand what it felt like to be immortal. Even if she lived through lifetimes, it would never compare to what Rhea felt. What Seteth felt. What it was like to lose everyone, and watch the ones who still lived lose their minds.

Sometimes, Seteth wondered what it would be like to die. He wondered if Rhea ever felt the same. If—it was so hard to bring himself to think it—Flayn ever felt that way.

His steps got more urgent as he thought of finding Rhea, in her room, dressed so ornately, after taking her own life. Why would she, after her one dream came true? Sothis had returned. What more could she have wanted? Even though his line of thought was rational, he knocked on her door with urgency. It was past midnight, but he knew that Rhea sometimes couldn’t sleep, just like him. But, since Sothis had fused with Byleth, maybe she had.

He heard the padding of her bare feet moving towards the door. He blinked, so long and slow that he almost thought he’d fall asleep right there. He became alert when the door creaked open.

Rhea had been sleeping. Her lids were heavy, her lips were parted in a sleepy haze. Seteth felt bitter, jealous. Of course she had slept. Sothis had returned in the form of Byleth, her dreams were coming true, her endless life suddenly had purpose. But what was left for Seteth, then?

“Lady Rhea,” he greeted, bowing.

“Seteth,” she said, with a bit of surprise. “You cannot sleep?”

“No. I cannot.” He paced himself, tried to temper his words. “I see you can. I...am glad.”

“It did not come easy,” she replied, frowning. He had offended her. Damn. Still, she stepped aside, offered him entrance wordlessly. He came in, then stood at the foot of her bed, looking at the mess of sheets that she’d been wrapped up in. “I understand why you might have trouble sleeping. All that has been going on with Byleth as of late...”

That wasn’t what plagued him. It was the  _ memories. _ Of war, of death, of pain that he, at times, hoped would kill him. How had she forgotten? “Yes. It has been very busy.”

“Lay with me, Seteth,” she said. She approached him from behind, but not before he heard the click of the lock. One hand was on his left breast, the other was on his abdomen. Her forehead was on the back of his shoulder. “I pray my company will soothe you.”

“Tonight, Rhea,” he declared. He turned around, watching as she reacted to his forward nature. She seemed confused, shocked. He was subservient to her, normally, but in situations like these...they were equals. Or, they had been. He was angry, he knew it. But he wasn’t wrong to be upset. Rhea had left him behind. She found her happiness and abandoned the solitude that they had found  _ together. _ It was madness, what she had done to Byleth. He hadn’t cared very much for the professor in the first place, but he couldn’t forgive Rhea. And yet... “Let me indulge in you tonight.”

“I’d never deny you,” she said, but the lilt in her voice made him think she had something else to say. He waited, but nothing came, so he led her to the bed. In the beginning, he had felt guilt for being attracted to her. She wasn’t his wife, she wasn’t someone he  _ truly _ loved...or, was she? Couldn’t love be found through something like that? Through suffering through the same circumstances? But that would mean he didn’t love her anymore. She wasn’t suffering anymore. He had never seen her so bright, so cheery, than when Byleth appeared with her emerald hair, her newfound power.

And Rhea hadn’t called for Seteth since. He wondered if she’d ever call for him again. He remembered the nights where she had  _ needed _ him, coming to his room with tears in her eyes, begging him to make her feel whole. And he did. He’d lay her on his bed, and he’d make love to her, for hours, until all of her sobs were moans; sometimes rough, sometimes soft. Whatever she had desired from him, he gave it to her.

Maybe she’d bedded Byleth already. Maybe someone else—the person she’d been longing for the whole time—had finally sated her. But Seteth had done all that he could, so why...

“Seteth,” she said. She was laying back on the bed, reaching up to place a hand flat on his chest. He hadn’t spoken for long moments. “Are you alright?”

“We ought to be quick.”

He gave no reason, but she nodded in agreement anyway. Seteth bit back tears, pulling at her nightgown, tugging at her underwear. She was looking at his face, he knew it, but he pointed his eyes to her breasts. He tried to stay his emotions, be tactical: he couldn’t sleep. That was all. Indulging in her body, sating himself, that was the only way he could sleep. He was just doing it to get some sleep.

Seteth lowered his head and took her nipple into his mouth, with just enough teeth to show his intentions. Rhea placed her hand on his head like a guiding mother, but her whimper of pleasure was far from familial. He bit down, curious to see her reaction; she gasped. “Seteth,” she said. He kept going, his hand parted her thighs, and she said his name again, but with more urgency. “Seteth!”

He lifted his head, his eyes dark. She almost seemed afraid of him. Maybe she was praying for Byleth to come save her, from the lonely shell of a man that he had become. “What, Rhea? What do you need of me?”

She had nothing to say. The hand on his head went to his cheek, cupping it. “You are going to hurt yourself, stressing like this. Please, be calm. Let me take over.”

Seteth had lost his dragon form long ago, but sometimes, he felt like a beast at heart. Rhea was the only one who was able to tame him...but for how long? How long until the caring soul that was reserved for him wasn’t for him anymore? Until then, Seteth had no choice but to let her have her way. Even if she was frustrating, distancing herself from him, he was still all that she had.

He let his body go a little slack, and Rhea rolled him over. Her bed was so large. He wondered if she ever felt lonely inside of it. He would warm it for her, he decided, as she gently divested him of his clothing and mounted him. Her motherly fingers traced over the contours of his muscles, and he shut his eyes. 

“Look at me,” she said. Seteth opened his eyes, against his will. He saw that she was smiling. “Seteth. Our dreams have come true.”

“Our...dreams?”

“Yes. The Goddess...Mother...” Rhea’s smile grew. “We have no reason to be afraid anymore.”

“But we do,” Seteth said, and Rhea leaned down and kissed him. She was twisted. He didn’t know how to react to her, what to say, because it was like she  _ didn’t _ understand anymore. He kissed her back, still, but his hands remained on the bed. She lifted her hips, those hips that had always enticed him, and held his shaft in her hand. “Rhea. Please.”

“And what might you be begging me for?” Ah, so she took it  _ that _ way. He wasn’t begging for her, not in the way that she thought he was. He was begging her to see the world for what it was, to see that nothing would change with the Goddess taking the form of Byleth. They would always be lonely,  _ together, _ so why would she abandon him? At least, for that night, he still had her. Even if she let him fuck her for weeks, months, years after, it would never be the same. Her heart would be elsewhere. He decided to treasure the dwindling love she had for him. He didn’t respond, and she saw his hesitance. “Seteth. Let’s not be at odds tonight.”

She silenced him, sinking down onto Seteth’s manhood with insistence. Her head tilted backwards, exposing the column of her neck. How he wished his fangs were as sharp as they used to be, so that he might tear into her skin. With that thought, he became rather self-aware, and held her hips to sate his need. He wanted to claim her, to hold her. 

Those first nights they were together, when his wife had passed and all was dark...those were the nights Seteth truly remembered. She let him do anything, he let her do anything. There were some things that made him nauseous when he thought about it. The nights where she’d whisper in his ear and tell him to go harder, when she’d beg him to choke her and his hand itched to be around her neck. When Rhea began to ride him, he was reminded of those nights.

Seteth wanted to take the reins, to take what he wanted so that he could wash himself of her and pretend she wasn’t forgetting him. But Rhea still held power over him, and she used it liberally. She laid her hands on his chest again, stabilizing herself. She was always so snug around him. He was long, but more than that, he had girth. There was a near-grimace on her face as she took him in, swivelled her hips to adjust.

He guided her down with his hands, moved her back up when she was in to the hilt. Slowly, she started to pick up the pace without his help. It burned when her nails dug into his chest, leaving two rows of crescent moons in his skin. She was wet around him, a relieving sign that she still got turned on at the thought of him. Seteth had never been so conscious of things like that. Not until she gave him reason to be.

Rhea was always tight, squeezing, his cock pressing against every inch of her walls. To see hips like those, propelling her up and down his length, all while she encased him in her warmth...it was all so familiar, but it felt new every time. Seteth began to thrust into her, using her hips to hold her in place. She cried out, but didn’t object, moving her hands to his shoulders for a better grip. “Oh, gods...C-Cichol...!”

That name. She was playing unfair. It had been centuries since he’d been referred to by that name. Even his late wife hadn’t called him by that name. He tried out her name, too, wondering if it would sound foreign to him. “Seiros,” he whispered. It tasted sour on his lips, but Rhea’s nails went deeper into his chest. He didn’t want to think about it all, about the horrible war that made them so damn lonely. But it was all behind her, then. Why would she be hurt to think about it?

“Cichol, Cichol,” she said, like a mantra, over and over. That name wasn’t as bitter as hers, he realized. The name Seiros reminded him of blood, of loss, while Cichol reminded him of the better days, when the land was bountiful because Sothis had given it to them, when he and Rhea had no need for nightly trysts. “Cichol!”

Did she feel him reacting to it? She must have. She kept saying it, with every moan growing more and more desperate. She was on top, but he began fucking her, not giving her a chance to decide their pace. For once, he didn’t feel powerless anymore, like the passage of time was sweeping him along without his consent. Holding Rhea close, hearing the name that earned him so much renown, and thrusting into her without a second thought...he felt that power again. He wasn’t alone, he was in control, for as long as Rhea could last atop him.

Yes, it was just like those first nights. “Harder,” she began to beg. “Harder, please, Cichol, I need you...”

There was a cold drop of sweat coming from his temple, moving towards his hairline. Seteth acknowledged her pleas not with words, but with harder thrusts. He might have been hurting her, he truly might have, with his hands gripping her so hard and his hips driving into her with abandon. But if it hurt, she didn’t complain. If it hurt, she loved it. The moonlight played across her skin. The sheen of sweat on her almost seemed like a glow.

“Rhea. Oh, Goddess, Rhea, I love you,” he breathed. 

“I love you, too,” she said. And that smile on her face was so damn honest, even though she was lying through her teeth. It was Byleth that she loved. He knew it. He was merely a placeholder, until Rhea got tired of him, until Byleth came to sleep in that bed, if she hadn’t already—

“Gods,” he growled. Easily, with his strength, he lifted Rhea off of him, then pushed her to her back. None-too gently, either. She gasped when he did, but he ignored her, placing his hands on either side of her head as he continued to fuck her. “Say it again. Please, say it.”

“I love you, Cichol,” she said. It sounded so  _ plastic. _ Like she was saying it just because she could.

Seteth had never hated himself so much. He was crying. She must have felt his tears when she reached up and cupped his cheek, because she moved her thumb as if to swipe them away, but they had already fallen. He moved her legs, put them over his shoulders, then moved deeper inside of her, listening to her yelp with every thrust. Rhea started to shudder beneath him, her ankles digging into his shoulder blades. She was going to climax, he knew it, but he didn’t care. He shut his eyes, tried to pretend it was anyone else, but he couldn’t. Cichol, Cichol, Cichol, she shouted, over and over. 

Rhea’s voice stuttered, and she put her hand on Seteth’s chest again, overwhelmed. One, two, three more jerks of his hips, and he buried himself inside of her, watching her pant and gasp for air as she orgasmed. He was right behind her, releasing rope after rope of his seed into her. That at least, Byleth couldn’t take from him. He’d finished inside of her so many times, but that night, he felt like he’d won something.

And it was all just a game to Rhea, probably.

As he’d expected, he felt worn after he’d finished. But not the kind of worn that was conducive to a good night’s sleep. He felt drained, empty. Rhea used her leg to pull him down to her, and he laid atop her, his head on her breast, his softening shaft still inside of her. She began to stroke his hair, pulling it back to kiss his pointed ears. “You are my everything, Seteth. Cichol. You mean everything to me.”

“And Byleth?”

The silence was deafening. He bit his tongue, wanting to see how long she’d hold out. How long until she realized that being a liar would come back to bite her. “Please. I already told you, I do not want to be at odds with you tonight.”

“We will not. Simply tell me the truth.”

“What truth is there to tell?”

“You’ve bedded her. She’s been here with you, just like I am right now,” he said. He lifted his head, stared holes into Rhea’s face. “Well? Am I wrong?”

“You are,” she said. When was the last time he’d heard her so angry? The Red Canyon? What did he do to deserve that tone, other than tell the truth? “You are very, very wrong. I’ve given my heart to you, Seteth. How could you—”

“Only because there was nobody else to give it to! And now that Byleth is here, things are different. It will only be so long before I am forgotten.”

Rhea pushed him away. Not much of a push, because Seteth was already climbing off of her. “And what does that say about me, letting you into my bed when my heart lies with another? I would never. Who are you trying to make me out to be?”

“You want her,” Seteth shouted. “Ever since that professor came here...I’ve felt it. You’re drifting away from me, Rhea! I should have known from the beginning, from the very second you let her in, that I was disposable to you. I am nothing to you now. After centuries of loneliness, you, the only one who truly understood me, have abandoned me. What do I do now, Rhea? Tell me.”

Seteth had never yelled at her like that before. All those years, and he had never imagined it. Seteth looked at her, and saw that she was trembling. She had pulled the sheets to her chest, as if she were hiding. Her eyes were hollow. “I’ve never slept with Byleth,” she repeated. Very dully. She had to have been lying, right?

“Even if you didn’t—”

“I’ve been lonely too, Cichol,” she said. She used her palm to swipe away tears. It was so rare that he got to see her like that. Then again, who else had challenged her? “You never wanted Mother back as much as I did. I know that. I’ve known that for a long, long time. But I would never,  _ ever _ abandon you! Even if a million of her were to come before us at this very moment, I would never forget that you were there for me. But don’t I deserve to be happy?”

Seteth looked at her with steely eyes. He couldn’t bear to look at her sullen face, because for a moment, it made him wonder if he was wrong. He couldn’t be wrong. He felt it in her touch, didn’t he? She was drifting away from him. He turned his back on her, collected his nightclothes, and redressed. He heard Rhea’s sobs, airy and light. He buttoned his shirt, and without looking, said, “I deserve to be happy, too, Rhea.”

“I want you to be happy. But what can I do? It’s never enough,” Rhea said. “Even when you would shut me out for days at a time, when you were at your lowest, I’ve always been there for you. Even when you’d come into my room in the middle of the night without a  _ word _ and touch me, I indulged you. And now Mother’s back, it’s all we’ve ever wanted, and—”

“No! It’s all  _ you’ve _ ever wanted,” Seteth replied, his fists clenched. “And you know I didn’t want this, you said it! And maybe I’ll never be happy again. Maybe it’ll always be this way, for as long as this damn life lasts!”

“Then I can’t help you,” said Rhea, darkly. “If you see nothing left for you in this life...then what can I do? Nothing will ever change. So much time has passed, and so many people have passed, but nothing will ever truly change. And I can’t stop that. I tried my hardest. But I won’t settle for staring into an abyss until someone decides to end me. I can’t. I’ve looked forward to Mother returning for so,  _ so _ long, because there was nothing else to look forward to.”

Seteth laughed wryly. “And now, what? We’re back where we started, and with a war on the rise to boot. Tell me what we do now, Rhea. Sothis has returned, your goal has been reached. If there’s nothing left for me, there’s nothing left for you either. The only reason I’ve been looking forward to this endless existence is because of you and Flayn, and now you’ve abandoned me. So, what now?”

Seteth stood, waited for Rhea to continue. But there was no argument. He knew it. With an infinite life, there was only so much to believe in, to do, to dream of. He was nearing the end, but there  _ was _ no end unless he made it so. Rhea hung her head, and Seteth swallowed his fighting spirit and left.

The walk back to his room seemed long. The halls were empty, Seteth’s skin was too hot. He crawled into his bed again, and stared at the ceiling. 

Tomorrow would arrive soon. He’d wake up, and...then what? Go to breakfast. Write out the next day’s schedule, execute that day’s plan. Serve Rhea. He laughed dryly. There was nothing else to do. No alternatives. What would he do, kill himself? And then what? Flayn would still live forever. Without him. Even if time moved so slowly, so cruelly, he still loved Flayn. So he had to live.

He thought and thought and thought. Then he watched the sun come up through his window. He hadn’t slept. It wasn’t his first night with thoughts like those, but it was the first night that he didn’t have Rhea to comfort him. He had to apologize to her, he decided. He might have been wrong about Byleth. Or maybe he was right. Either way, just like Rhea had said, there was still a place in her bed, in her heart, for him. Even if it was temporary, he had Rhea. Rhea would welcome him.

_ And after Byleth is all hers, after she’s finally left me completely... _

Seteth sighed. Well, no matter. In the meantime, someone had to keep the monastery running.

**Author's Note:**

> Being immortal must really suck. I think that's the majority of why I wrote this. Like, seriously, it must really suck. Just wanted to showcase that. Like, imagine being immortal. At some point you have to think, "What's left for me to do? What's the point of going on?" which resonates strongly with how some experience depression. And similarly, sometimes you just keep going anyway. Even if you don't see the point.
> 
> Y'know even while writing this I wasn't sure if Rhealeth had happened in this or not. I just sort of wrote. so if you're wondering...don't ask me. open to interpretation, i guess


End file.
